Magazine plate back for cameras



W. LUDOWICI MAGAZINE PLATE BACK FOR CAMERAS Feb. 27, 1923. 1,446,803

Filed June 25, 1920 Patented Feb. 27, 1923.

UNITED srArEs' arana: caries.

WILHEmvr-LUDOW or, MUNICH, GERMANY.

M AGAZIN E PLATE BACK FDR CAMERAS.

Application filed June 23, 1920. Serial No. 391,002.

To all w/aom it may concern:

Be it known that I, \VILHELM LUnowIoI, acitizen of the Republic of Germany, residing at Munich, Germany, have invented certain new and useful Improvements in Magazine Plate Backs for Cameras; and I do hereby declare the following to'be a full, clear, and exact description of the invention, such as willenable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to letters or figures of reference marked thereon, which form a part of this specification.

Magazine platecameras with two rows of plates, the uppermost and lowest of which can be shifted by means of pairs of racks actuated by a common shaft, are wellknown.

This invention relates to a kind ofmagazine plate back which is distinguished by many advantages as compared with those already known. First of all, any desired number of plates (up to100 for instance) can be stored in this magazine plate back, because the row of plates is raised mechanically and positively in a way excluding any breakage of plates. The rotation of the driving shaft is also effected mechanically and imparted by an equally directed mo tion, thus assuring shock-free working of the several parts even when plates are rapidly changed. Finally, the back does not form a camera for itself, but may be arranged on any camera adapted to receive several rows of plates. It is equally suitable in all cases where a considerable number of plates must be carried along. as for instance especially for balloon and aeroplane photography. The new feature of the invention consists in a crank drive rotating in one direction only and arranged on the outside of the back, the crank disk of said. drive being formed as a cam disk and the connecting rod thereof as a rack, the forn'ier thus actu ating the cam lever which raises the row in. reserve. and the latter the shaft provided for driving the pairs of racks.

Reference is to bemade to the accom panying drawing, forming a part of the specification. in which similar characters of reference indicate corresponding parts in all the figures.

The accompanying drawing illustrates by way of example an embodiment of a magazine plate back of this kind.

Fig. l is a longitudinal section on the line 1-1 ofFig. 3, and

Fig. 2 a side elevation, the protecting front wall being omitted.

Fig. 3 is an enlarged cross-section on line 3 01 Fig. 2, and

Fig. 4 shows in plan part of the plate shifting device. l

The magazine plate back consists of the oblong tin casing a dividedby the partition wall 1) into two compartments in which plates (1 are stored, the plates being inserted. or removed from the casing through the two ends thereof which are normally closed by the removable slides a In the centre ofthe partition wall'b the shaft d is supported which actuates the two pairs of racks f forwards and backwards by means of the pinions e. Said racks carry at their ends spring claws g situated laterally to their racks (see Fig. 4). This enables one to arrange the claws In any desired width and to I assure thereby a reliable seizing of the plates even if they are thin. This arrangement also involves another great ad *antage, because it enables the spring claws g to move upwards and downwards, which is of great impor' Lance for the left-hand row as the plates of this row are placed obliquely as described hereinafter, such movementbeing only possible with the said claw arrangement.

The back casing a supports on one of its longitudinal sides the crank drive. proper, comprising the crank disk 71. and the connecting rod 7i: (Fig. 2). The crank disc carries a cam v, inthe path. of which lies lever Z rigidly connected to the shaft m extending over the whole width of. casing a and arranged inv a closed housing m on the underside of the latter. The shaft m carrics two cam levers n resting against the frame of the plates (Fig.3).

The connecting rod is formed as a rack which engages a pinion 0 keyed to the shaft (I. said pinion o and the pinions 0 having a suitable ratio of gear. The connecting rod /r is guided on its free end by a sliding membeer 7 movably pivoted to the shaft (7, and thus following the reciprocating motion of the connecting rod. Y 1 i The operation of this drive is .as follows:

The crank disk It always roiates in the same direction (see direction 0 the arrow in Fig. 2), this being effected by means of a crank lever m mounted on the shaft w of the crank disk (as shown in dotted line in Fig. 3) or mechanically by means oi flexible shaft or the like. By the rotation oi. disk It the connecting rod K and thereby the shaft (Z and thus the pairs ol racks f are set in a. reciprocating or backward and forward mot-ion respectively. In consequence thereoi the claws g seize and horizontally shift the uppermost and lowest plates of each row, this position being shown in lFig. 1. By the rotation of disk h the cam 'U of the latter has meanwhile reached and pressed downwards the lever Z and pushed upwards the cam levers it. These levers now raise the whole row obliquely as shown in Fig. 1, enabling the uppermost plate of the left-hand row readily to be shifted over the partition wall Z), and the lowest just exposed plate of the right-hand row to be shifted just as readily beneath the other plates. Any suitable means to permit exposure of the last mentioned plate at the proper time may be provided. l have shown an apertmre, in the bottom of the casing normally closed by a suitable cover a which may be removed at ter the casing has been. placed in position in the camera. The position of cam a corresponds of course in each case with the position of the connecting rod in such manner that the control of the cams it causes the latter to raise the respective plates when the motion of the plates commences. In order to equalize the unequal turning forces which arise during the reciprocating motion of the connecting rod laand thus to assure a smooth working of the mechanism, a coiled spring 1" is provided (Fig. 2). One end of this spring is secured to the shaft (Z and the other end to the wall of the casing at s or located in the mechanism at another suitable point, thus facilitating the drive and overcoming without shock the dead center positions (at the end positions or the connecting rod and racks). In order to protect the upper plates of both rows from slipping, thin plate springs ii are provided on the underside of the upper wall of the casing (appearing in Fig. 3only) which slightly rest against the upper plates without in any way hindering the shifting ot the plates.

The crank drive h,7cpresents many advantages. On one hand the employment of any violence in operating the mechanism is rendered impossible, and on the other hand a reduction of speed at the points of reversal is realized, enabling thereby the spriig claws reliably to seize the plates 0 and the latter slowly to commence their shifting motion. Owing to its direction o'lf rotation remaining always the same, this crank drive precludes an insutficient change of plates. liinally, no slipping oi the upper .most plates in the neighbouring row can occur, by lateral shocks for instance or with an oblique position. of the back, which happened in the well-known cameras provided with plates which were continually pressed upwards by springs. The left-hand row only raised while changing takes place, and even then not higher than is necessary for enabling the uppermost plate readily to slide over the wall Z).

Having described the nature of my in vention, what I claim as new and desire to secure by Letters Patent 01": the United States is:

1. A magazine plate holder, comprising a casing adapted to contain two rows of plates, rack'bars arranged on opposite sides of the rows, means on the bars to successively engage the plates of each row at Opposite ends, pinions engaging the rack bars adapted to move the latter simultaneously in opposite directions, and a rack and pinion mechanism for actuatin said pinions.

2. A magazine plate holder comprising a casing adapted to contain two rows oi plates, rack bars arranged on opposite sides of the rows, means on the bars for successively engaging the plates, a shaft, pinions on the latter in mesh with the rack bars, a driving member on the shaft, a crank disk, and a rod-connecting the latter and driving member.

3. A. magazine plate holder comprising a casing adapted to contain two rows of plates, rackbars arranged on opposite sides of the rows, means on the bars for successively engaging the plates, a shaft. pinions on the latter in mesh with the rack bars, a driving pinion on the shaft. a rack bar meshing with the driving pinion, and acrank disk for reciprocating the last named rack bar.

a l magazine plate holder comprising a casing adapted to contain two rows of plates, rack bars, arranged on opposite sides of the rows, means on the bars for successively 'engaging the plates. a shaft, pinions on the latter in mesh with the rack bars, a driving member on the shaft, a crank disk having a cam termed thereon, a rod connecting the crankdisk and driving member, a shalt adapted to he oscillated by said cam, and. cams n the last named shaft for intermit tently shitting one row of plates.

in testimony that i clain'i the foregoing as my invention, l have signed my name.

winnnnn nunowici. ll itncsses: i

Fm TEAUTMANN,

ANNA Srtinnn. 

